It is well known to provide an inflatable air bag for restraining a vehicle occupant. The air bag assembly includes a folded bag which is connected to a source of inflation gas. Release of the inflation gas into the air bag causes the bag to expand rapidly so that a face wall of the air bag is displaced toward contact with the occupant. It is well known to provide one or more vent openings in the walls of the air bag to vent inflation gas from the interior of the air bag into the occupant compartment. These air bag vents are commonly provided in a base wall portion of the air bag to direct the vented gas away from the occupant. The vent opening may be provided by a gas permeable fabric panel sewn into the bag. In addition, it is well known to employ various flow control devices to control the flow of inflation gas through the vent opening.
The present invention provides a new and improved air bag assembly in which the degree of opening and closing of the vent is dependent upon the displacement of the air bag toward the fully deployed position.